I wonder if it would be possible to replace the speaker in the KX2? Of course, if it’s not the speaker, but rather the audio circuitry feeding it, it could be a simple (add capacitor) or complex (replace stage) fix. Perhaps Eric Swartz, WA6HHQ at Elecraft could help. He’s a very approachable guy - and he was at FN.
I know changing the speaker in my FT-817 for one that was designed for Model Railway usage (!) made a big difference for my hearing.
73 Ed.
The real issue is the speaker faces down on the KX2 and if it’s noisy/windy then the sound gets lost. I have a small sealable plastic box I carry the paddle, pencils, an LCD clock and some wee patch leads (SMA to BNC cable to attach handy to the aerials) etc. and I stand the KX2 on that so the sound reflects back. The front mounted 705 speaker is aimed at your face and I think the amp has a lot more oomph. There’s not really any space in the KX2 for a bigger speaker unless you drill the battery cover and place one in there and don’t use the internal battery pack.
Perhaps someone can design a 3D-printed audio reflector add-on that can simply clip onto the KX2?
73 Ed.
Good Day all,
There is a free app on the Apple and Android stores called 705 remote that is easy to setup with easy to follow instructions and works with an Apple Watch apparently (not tried that feature), you can leave the 705 in the bag using the ICOM mic with built in speaker for QSOs or connect a Bluetooth headset or AirPods to the rig.
I purchased the SDR mobile works great for remote control of the ICOM 705 at home over the home network and locally on summits for digi modes or cw, you have the option to use the built in mic and speaker on the phone.
Having owned a a KX2 and a KX3 I would class the KX2 as the top contender in the minimal QRP transceivers, reason being you need to bring an additional handheld or transverter to operate on the VHF/UHF bands. The IC 705 has all the bells & whistles included as similar transceivers you would need to purchase these after market or add on modules.
When I first got the IC 705 I was unsure of it to many sub menu buttons to operate but the more you use it and set it up to your preference the easier it becomes to use. I have sold my KX range and ft817 to purchase a K3 for the QTH and IC705 both at a fair used price, I would probably be tempted to bring the K3 on a few drive on short walk summit activations for special sota activities for the extra power.
Ideally if I had the money a KX2 added to the equipment would be great for those days doing multiple activations if you are wanting to keep the weight to a minimum but operate on as many bands/modes possible. Been keeping a watchful eye on the QMX 5 band transceiver hoping that SSB gets added soon think this will be interesting rig for SOTA.
Nearly forgot after market ATUs designed for the IC705 are useless tried a few and sold them nothing beats the KX elecraft range, wish ICOM would have put some effort in to this.
Prior to selling the KX3 and FT817 I done some weight comparison and weighed the three different rigs on the kitchen scales all with their internal batteries, mics and a kanga qrp atu (ft1d with the kx3) for fairness to help make my decision.
ICOM 705 battery & atu 1.33kg
Ft817 battery, ext keyer & atu 1.38kg
Kx3 internal atu, envelope batteries & ft1d 1.29kg
73
Graeme
Andy, this is a great topic and one that I’ve been considering for some time.
I have an IC-705 and activated with it only once. It did work well and I was satisfied with it. However, I normally use an FT-891 for activations. My pack is ~25lbs fully loaded and I guess I’m an example of the hire-a-sherpa-service that Alan suggested, lol, but I don’t mind the added weight and the extra set-up time using the 891, a tuner, a 4.5Ah battery, a 30ft mast and an end-fed wire.
Recently, after an activation with a local ham here in Kentucky (who was using a KX3), I was very impressed with it’s small size and I decided to start saving for a KX2. It’s going to take me a while longer to reach my savings goal, but after reading remarks about the KX2’s case being open with multiple holes to allow for moisture to creep in, the need for headphones as the speaker volume is very weak, and that one good sneeze may cause it to fall to bits I might reconsider.
Additionally, I’ve been hesitant to pay Elecraft $1,600+ for the KX2 shack in the box kit whilst having to wait 12-16 weeks to receive it.
IDK for now, but this is all very good information from firsthand users. Many Thanks to you for posting on this topic!
Bob -W4BTH
There’s some poetic licence at play Bob, you need to take that on board.
The issue is the KX2 feels lacking. But I don’t think I’ve heard of anyone yet who uses a KX2 for SOTA who has had one fail on an activation. I’ve heard of one or two overheating in the W5 summer sun and having to cool down, not a problem in GM. I’ve seen in drizzle, water start to creep under the perspex display cover. But I have the fix for that now, don’t laugh because the price is right. Disposable Shower Bath Caps Hat Waterproof Clear Hair UK Seller Free Delivery | eBay. A handful of these in the SOTA bag weigh nothing and work perfectly to cover up any ingress. You can slip one over the KX2 and still see the display and press the buttons. I know a few people have worn out the rotary encoder, did that on my old 817, nothing special there. And there have been the odd component failure but no more than other radios.
I’ve dropped my KX2 from waist height onto grassy summits, oh did I swear. I had cramp three times on one activation and every time I jumped up to stop the cramp I kicked the KX2 with US size 10.5 leather boot hard and it flew away. Didn’t even change frequency or mark the case! And I swore a lot again, especially the 3rd time I did it.
I would still buy a KX2 without hesitation. It’s just not perfect. Probably only 85% perfect. And I can read the display on a KX2 without glasses unlike my 817. I need the 705 as I need 2m for my 23cm transverter and 70cm for my 13cm/3cm transverters.
This is probably the third time you’ve mentioned something in a random thread where I’ve thought, that’s exactly what I need. I have several shower caps that my mother-in-law saved me from a cruise or hotel room that she gave me for covering a bread tin while the dough proved. One of these would probably be perfect for covering my homebrew rig if I get caught in an unexpected shower. (If it’s raining or highly likely to [i.e. most days in Britain] I set up the tarp).
RE: shower cap. I mentioned that in my post above:
I don’t remember where I learned that trick, but I have been carrying them since 2018. Works on the KX3 too!
I consider this to be standard regardless of the rig used. I guess this is down to looking for long distance QSOs on 2m from summits. Not all rigs have sufficient audio output to combat howling winds, certainly those aimed at low power consumption.
Bob,
I recommend the KX2 for serious SOTA activators where there is a decent length track to the summit or a significant but of rock/ice climbing. Andy is apparently in the habit of adding an anvil to his kit if it seems too light, 
. Seems you could be in that category.
I have owned and activated with other Chinese rigs in the past, a 20 W thing and a RS918 clone. That was a quarter the price of a KX2 but lacked an ATU. It was possible to customise the internal software - for example I reduced the tuning step size for CW.
I sold it and got a KX2. I’ve not made any contacts I could not have made with the RS918. And I don’t use antennas that really need the full capability of the KX2 ATU.
But I have all those bells and whistles available. And the spectrum is cleaner and it doesn’t have an annoying ghost on the screen.
The one weakness of the KX2 is it shuts down after 5 minutes in direct sunlight in VK. It has sacrificed weight for heat dissipation, as have many small sets.
The non factory heatsink helps but it’s best to keep well shaded and ventilated
Now, going off at a tangent, which is a requirement for this Reflector. The AH705 ATU is the only game in town if you have an IC705. It has a wider range than the KX2 tuner and can be placed remote from the operating position, on the ground or up a mast.
73
Ron
VK3AFW
Sitting inside because it might rain.
The AH-705 is excellent. A strange beast, but excellent. It’s works just like a miniature AH-4 / AH-730 remote tuner. A BNC on the input and SO239 on the output - seemed daft to me at first. Actually, it makes it quite versatile - it takes a 4mm banana plug directly for a random wire (will tune virtually anything), or a balun. The control cable is terminated in 3.5mm TRS, which costs pennies. There is a little bracket supplied, which allows it to be mast mounted. Below is mine, mast-mounted feeding a doublet, via 4:1 balun. After the frustration of a flaky mat-10 tuner, this is a pleasure to use.
If you want a waterproof HF radio, then the Discovery TX-500 is the way ro go. I’ve found the KX2 to be pretty robust. I always male sure to dry it out in a warm place after a damp activation. Would an icom IC-705 be any better protected?
The speaker audibility is only an issue if the radio is lying flat on the ground, as Andy says.
Thank you for that additional info. I will take it on board. It does sound like it’s pretty rugged.
Thank you I’ve looked at the TX-500 and will check it out in more detail. I’ve done the same with my damp FT-891 sitting on the tailgate to dry out. I don’t think the IC-705 would fair much better, but it does have the rubber inserts on the input jacks. Also good to know speaker is ok. Many Thanks!
Thank you Ron. I appreciate the additional info! The one activation I have made with the IC-705 was with no tuner and an end-fed wire on 40m. It worked great and I need to use it more often.
I had a look at this. The UK price £299 was scary. Then I looked to see how much used, second-hand Elecraft T1 ATUs sell for (when you can get them) and the new price for AH-705 is not that wild.
Andy,
Do I understand correctly that the AH-705 requires the proprietary control cable to the IC-705 in any case?
So it is not a classic auto-tuner or a “semi-automatic” tuner such as the Elecraft T1 with the option of starting the tune cycle remotely?
Yes. The cable is not proprietary though. It’s a simple audio cable terminated with 3.5mm TRS connectors.
I baulked at the price too but an ex-display model popped up at the right moment at a decent discount.
Thanks, but by proprietary I meant the information exchanged via the control cable between TRX and ATU.
